Tensioning device



Feb 25, i936.,

G, L. MATTHEWS El' AL TENSIONING DEVICE f @enf/0715 zy Nczfgew ma:

Harry zlel Patented Feb. 25, 1936 UNHTED STATES PATENT OFFICE TENSIONING DEVICE Application July 30, 1932, Serial No. 626,343

13 Claims.

This invention relates to tensioning devices, and particularly to a device for tensioning cords, strings, gut, etc., wherein the degree of tension placed on the cord or string may be positively determined.

One object of the present invention is to provide a tensioning device which is relatively light in weight, portable, easy to handle, and wherein the tension exerted by the use of the device is completely and entirely under direct control of the operator.

Another object of the invention is to provide a tensioning device wherein the degree of tension exerted is positively indicated to the operator.

Another object of the invention is to provide a tensioning device which may be operated by a minimum expenditure of physical effort.

Another object of the invention is to provide a tensioning device which will enable one to obtain uniform tensioning of strings, as for example, in the Stringing of a tennis racket, or the like, without long practice and experience in the work.

A further object of the invention is to provide a tensioning device having cord or string gripping means associated therewith, which enables the operator to easily hold the cord while tensioning, and which provides suitable protection against crushing or otherwise damaging the cord.

A still further object of the invention is to improve devices of the character described in sundry details hereinafter referred to and particularly pointed out in the appended claims.

One embodiment of the present invention is shown for illustrative purposes in the accompanying drawing, in which Fig. 1 is an elevational view of our improved tensioning device illustrating its use in Stringing, and tensioning the strings of a tennis racket, or the like;

Fig. 2 is an enlarged elevational view of a portion of the tensioning device illustrated in Fig. 1, having portions thereof broken away to facilitate the showing of certain structure embodied in the device, the view being taken substantially as indicated by the line 2-2 of Fig. 3; and

Fig. 3 is a longitudinal sectional View taken substantially as indicated by the line 3-3 of Fig. 2.

The racket shown in Fig. 1, in connection with which the use of the present invention is illustrated, comprises a frame 5 including a handle 6, the frame 5 being provided with main strings 'I and cross strings 8 threaded through portions of the frame 5 in the usual manner.

The illustrative embodiment of the present invention as shown in the drawing comprises a main supporting member or frame indicated as a whole by the numeral 9, and comprises a shank portion II having a hand grip I2 formed at one of its ends, and a head I3 formed at the opposite end thereof, the head I3 having a cord holding surface I4 extending laterally and substantially transversely to the shank portion I I of the supporting member, and having a longitudinally extending ange portion I5 offset with respect to the shank portion.

For securing a string, gut or cord, as for example, the cross string 8 of a tennis racket, against the cord holding surface I4, a gripping jaw I6 is slidably mounted on the shank portion I I between guide anges II and I8 formed thereon, the jaw I6 being arranged in a manner to have a rectilinear movement. with respect to the shank portion. The gripping jaw I6 is provided on its string or cord engaging face with a compressible material I9 such as rubber, felt, or the like, for providing an eflcient frictional engagement with the cord or string without damage thereto by reason of any crushing effect which otherwise might result from the gripping of the cord or string between the cord holding surface I4 of the head I3 and the gripping jaw I6.

For actuating the gripping jaw, a movable hand grip 2I in the nature of a bell crank lever is pivotally mounted intermediate its ends at 22 on a laterally extending lug 23 formed on the supporting member or frame 9, the short arm 24 of the bell crank lever or movable hand grip 2l being provided with an elongated aperture 25 adapted to receive a pivot pin shown in the present instance as a screw 26 mounted in the gripping jaw I6 at the lower or opposite end thereof from the string or cord engaging face material I9, and for separating the hand grips I2 and 2l to release the string, a spring 2'I is positioned between the grips preferably adjacent the pivotal connection 22.

It will be observed from the foregoing description that the cord or string 8, for example, may be conveniently and quickly positioned between the cord holding surface I4 and compressible material I9 of the jaw face, and that by drawing the hand grips I2 and 2l together, a force or pressure will be exerted upon the string in a manner to hold it securely between the surface I4 and material I9 with very little effort on the 50 part of the operator. The head I3 is provided with a plurality of guide pins 28 for properly positioning the cord with respect to the surface I4 and face of the jaw I6, and it will be observed that upon releasing the operators grip, the spring 55 2l will separate the hand grips I2 and 2|, and that through its connection with the short arm 24 of the movable hand grip 2|, the gripping jaw I6 will be moved to disengage the compressible material I9 from engagement with the cord.

Mounted on the shank portion II in a manner to have a rectilinear sliding movement with respect thereto is a pressure member or indicator actuatingshoe designated asV a Whole by the numeral 29, the said shoe having a contact portion 3| formed thereon in substantial alignment with the body of the device and in spaced relationwith respectto adjacent gripping or Ven-Y 1 gaging portions of the head I3 and jaw |55.

For slidably mounting the pressure -rnember 29 on the shank portion I I of the supporting member or frame 9, the member 29 is provided with an elongated aperture or slot 32 adapted to receive a bolt 33 screw-threaded into the shank portion II, and for maintaining the member 29 in substantial alignment with the main supporting member 9 or body of the device, thepressure member 29 is provided with guide portions 34 and 35 positioned on opposite sides of theshank portion I |in a manner to have a sliding engagement therewith. Y f

For yieldingly maintaining the pressure member 29 and its contact portion 3| in'predetermined normal position Vwith respect to the head I3 and in spaced relation with the cord holding surfaceV I4V thereof, a resilient member shown in the present instance as a coiled spring 36 ispositioned Ybetween the inner side of the cord holdingportion |4 of the head I3 andthe inner side of the contact portion 3| of the pressure member 29, the spring 39 being secured against lateral displacement by means of lstuds or pintles 31 and 38 formed on the pressure member 29 and head |3, Arespectively, and adapted `to enter the opposite open ends of Vthe'spring. Y

The spring 36 shown in the present instance is ofthe compression type and actsto normally separate the contact portion 3| of the pressure member 29 and the cord holding surface I4 of the head Iii-and to maintain the lower end of the slot Y32 in engagement withzthe pin 33 as clearly shown in Fig. 3. Y Y

Rotatably mountedV in the flange portion I5 of the head I3 is a shaft 39, to one' end of which' is securedan indicator nger'lll adapted to cooperate with a scale 42 (see Figsfl and 2) formed on the flange portion I5 andwhich may be p rovided with suitable graduations and indicia to indicate various degrees of tension. To the opposite end ofthe shaft 39 is secured a pinion 43 adapted toV mesh with a rack 44 rigidly secured' adjacentl one of its ends to the contact portion 3| of the' pressure member 29, the arrangement being such that any rectilinear movement of the pressure member 29 with respect to the head I3 will be transmitted through the rack 44, .pinionA 43 and shaft 39vto the indicator nger 4| in a manner to move the free end of the nger along the scale 42 formed onY the flange Vportion I5 of the head I3. Thus, it will be observed that the spring 36, through its connections with the shaft` 39 as above described, serves to yieldingly :resist rotation of the shaft, and permit movement there.-

Yof andY of the indicator finger 4| only in accordance with the movements of the pressure member 29. i Y Y In the Stringing and tensioning the strings of a tennis racket, for example, the operation of the device is substantially as follows: the string or gut,` may be threaded through apertures formed in the frame of the racket and provided for that purpose, each run or strand of the gut after tensioning being anchored in any suitable manner as by means of an awl 45 (Fig. 1) as is the usual practice. The strand or run of the gut to be tensioned, as for example the cross string 8a shown in Fig. l, is then gripped between the cord holding surface |4 of the head I3 and the compressible material I9 of the gripping jaw I6 after the manner shown in Fig. l, the tensioning device, preferably, being positioned with respect to the racket frame 5 substantially as shown in Fig. l, with the contact portion 3| of the pressure member 29 in engagement with the outer surface or edge of theY frame 5 and the ilange portion I5 of the head I3 and a flange 46 formed on the pressure memberV 29 extending on opposite sides of the racket frame 5 in a manner to crumyand in the direction indicated by the ar- Y row 41 of Fig. 1, will cause a tensioning ofthe string or gut 8a and a pressure to be exerted by the contact portion 3| against the edge of the racket frame 5 in a manner to cause theV pres-V sure member 29 and rack 44 to move relatively tothe head I3, such movement of the racl -44 causing the pinion 43 and shaft 39 to rotate, thereby moving the indicator nger 4| along the scale 42 in amanner to indicate the degree of Vtension exertedupon the particularV run or strand of gut being operated upon, after which, and While the tension on the string 8a is maintained,"the aWl 45' maybe withdrawn from the position illustrated'in Fig. 1 and inserted in the aperture 48 of the frame 5 in a manner torwedge the tensioned strand therein until the gut is again threaded across the racket, andthe tensioning device applied thereto at the opposite side of the frame for tensioning the next'strand or run of the gut in the manner above described.

It will be observed from the foregoingdescription that the present invention provides a tensioning Vdevice by theV use of which suitable tensiononthestringsmay be obtained without great physicaleifort on the part of the operator due to the leverage possible by reason of the relativeV positions of the cord andracketrframe engaging portions of the device, and that by reason of the Y connection between the indicator nger 4| andV the pressure member 29, Vforming a parteiV the tensioning mechanism, Vthe various strands or runs of the cord or gut may be provided with measured uniform tension which is most ydesirable in many instances particularly in tennis rackets,or'the like, and it will be observed also that by use of the present invention, a most eicient Stringing or restringing job .may be accomplished by an `operator without having had any` particular amount of practice or experiencein Work-of this kind.

It will ofcourse be obvious, that the tensioning device, of the present invention may be used in tensioning of the main Ystrings '|-of a racket'as well as the cross strings thereof, its use in connection Withthe latter, as shown invFig. 1, being merely illustrative. r

Obviously, thepresent invention is not limited Y to Vthe Vprecise construction and arrangement shown and described as the same may be variously modified. Moreover, all the features of the invention need not be used conjointly as the same may be used to advantage in various different combinations and sub-combinations.

What we claim as new and desire to cover by Letters Patent is:

1. In a tensioning device, the combination of a head, a manually actuated gripping jaw having a compressible material on its face cooperable with said head for securely holding a cord therebetween, and a yieldable pressure member mounted on said head and movable with respect thereto, said member having a contact portion spaced from adjacent cord holding portions of said head and jaw and adapted to engage a relatively fixed portion of an article on which the tensioning device is used.

2. In a, tensioning device, the combination of a main supporting frame having a hand grip formed thereon, a head formed on said supporting frame, a movable hand grip pivotally mounted on said frame, a gripping jaw pivotally connected to said movable hand grip and having a compressible material on its face cooperable with said head for securely holding a cord therebetween, and a pressure member mounted on said head and movable with respect thereto, said member having a contact portion spaced from the cord securing portions of said head and jaw, said contact portion being adapted to engage an article on which the tensioning device is used.

3. In a tensioning device, the combination of a head, a manually actuated gripping jaw engageable with said head for securely holding a cord therebetween, a pressure member mounted on and movable with respect to said head and having a contact portion adapted to engage an article on which the tensioning device is used, said portion being spaced from the engaging portions of said head and jaw, resilient means for resisting the movement of said pressure member, and tension indicating means operatively connected to said pressure member in a manner to be actuated thereby.

4. In a tensioning device, the combination of a head, a manually actuated gripping jaw cooperable with said head for securely holding a cord therebetween, a pressure member mounted on and movable with respect to said head and having a contact portion adapted to engage an article on which the tensioning device is used, said portion being spaced from adjacent cord holding portions of said head and jaw, and resilient means for resisting the movement of said pressure member with respect to said head.

5. In a tensioning device, the combination of a head, a manually actuated gripping jaw engageable with said head for securely holding a cord therebetween, cord engaging guide pins mounted on said head, a pressure member mounted on and movable with respect to said head and having a contact portion adapted to engage an article on which the tensioning device is used, said portion being spaced from the engaging portions of said head and jaw, and resilient means for resisting the movement of said pressure member with respect to said head.

6. In a tensioning device, the combination of a main supporting frame, a head forming a part of said frame, a manually actuated gripping jaw engageable with said head for securely holding a cord therebetween, a pressure member mounted on said supporting frame and movable with respect to said head,.said pressure member having a contact portion spaced from the engaging portions of said head and jaw, resilient means for resisting the movement of said pressure member, a graduated scale on said frame, and an indicator finger associated with said scale and operatively connected to said pressure member in a manner to be actuated thereby.

'7. In a tensioning device, the combination of a main supporting frame having a hand grip formed thereon, a head iormed on said frame, a movable hand grip pivotally mounted on said frame, a gripping jaw operatively related to said movable hand grip in a manner to be actuated thereby and engageable with said head for securely holding a cord therebetween, a pressure member mounted on said frame and movable with respect to said head, said pressure member having a contact portion spaced from the engaging portions of said head and jaw, resilient means for resisting the movement of said pressure member, a graduated scale on said frame, and an indicator finger associated with said scale and operatively connected to said pressure member in a manner to be actuated thereby.

8. In a tensioning device, the combination of a main supporting frame having a hand grip formed thereon, a head formed on said frame, a movable hand grip pivotally mounted on said frame, a gripping jaw pivotally connected to said movable hand grip and engageable with said head for securely holding a cord therebetween, a pressure member mounted on said frame and having a contact portion spaced from the engaging portions of said head and jaw and movable with respect to said head, resilient means for resisting the movement of said member, an indicator nger pivotally mounted on said head, and means operatively connected to said finger and pressure member for actuating the iinger in accordance with the movement of said pressure member.

9. In a tensioning device, the combination of a main supporting frame having a hand grip formed thereon, a head formed on said frame, a movable hand grip pivotally mounted on said frame, a gripping jaw connected to said movable hand grip and having a rectilinear movement with respect to said supporting frame, said jaw being cooperable with said head for securely holding a cord therebetween, a pressure member mounted on said frame and having a contact portion spaced from the engaging portions of said head and jaw and movable with respect to said head, resilient means operable between said member and head for resisting the movement of said member, an indicator finger pivotally mounted on said head, and means operatively connected to said nger and pressure member for actuating the nger in accordance with the movement of said pressure member.

10. In a tensioning device, the combination of a main supporting frame having a hand grip formed thereon, a head formed on said frame, a movable hand grip pivotally mounted on said frame, a gripping jaw connected to said movable hand grip and having a rectilinear movement with respect to said supporting frame, said jaw being engageable with said head for securely holding a cord therebetween, a pressure member mounted on said frame and having a contact portion spaced from the engaging portions of said head and jaw and having a rectilinear movement with respect to said head, resilientl means operable between said member and head for resisting the movement of said member, a graduated scale formed on said head, an indicator linger pivotaliy mounted on said'head adjacent said scale, and means operatively connectedto said linger and pressure member for actuating the finger in accordance with the movement of said pressure member.

11. In a tensioning device, the combination of a supporting frame having a hand grip formedV thereon, a head formed on said frame and having a flange portion extending longitudinally thereof, a movable hand grip pivotaily mounted on said frame, a gripping jaw connected to said movable hand grip and having a rectilmear movement with respect Vto said supporting frame, said jaw being engageable with said head for securely holding a cord between the jaw and head, a pressure member having a flange formed thereon and mcvably mounted on said frame, a contact portion on said pressure 12. In a tensioning device, the combination of a main suppcrtingframe having a hand grip formed thereon, a head formed on said frame a movable hand gripV pivotally mounted on said frame, a gripping jaw connected to said movable hand grip .and having a rectilinear movement with respect to said supporting frame, said jaw being engageable with said head for securely holding a oord therebetween, a pressure member mounted on said frame and having a contact portion spaced from the engaging portions of said head and jaw and having a rectilinear mcvement with respect to said head,Y resilient means operable between said member andhead Vfor Yresisting the movement of said member, a

graduated scale formed on said head, a shaft rotatably Ymounted in said head, an indicator ringer mounted on said shaft and operatively related to said scale, a pinion mounted on said shaft, and a toothed rack carried by said member and operatively connected to said pinion for rotating said shaft and moving said linger in accordance with the movement of said pressure member. s

V13. In a tensioning device, the combination of a main supporting frame having a hand grip formedthereon, ahead formed on said frame and having a flange'portion extending .1ongi tudinally thereof, a movable hand grip pivotally mounted on said frame, a gripping jaw connected to said movable hand grip and having a rectilinear movement With respect to said supporting frame, said Yjaw being engageable with said head for securely holding a cord between the jaw and head, a pressure member having a flange formed thereon movably mounted on said frame, a contact portionion said pressure member between said flange and the iiange portion of said head,

Ysaid Contact portion being spacedfrom the en'- gaging portions of said head and jaw and movable With respect to said head, a spring operableY between said member and head for resisting the movement of said member and contact portion,

YaY graduated scale formed on'said head, a shaft rotatablymounted in said head, an indicator `nger secured to said shaft and operativelyre'e Y lated to said scale, a pinion secured to said shaft, and a toothed rack carried by said pressure member and operatively connected to said pinion for rotating said shaft and moving said linger along said scale in accordance with the Ymovement of said pressure member with respect to said head.

Y GUY L. MATTHEWS.

HARRY L. DIEHL. 

